Quote Originally Posted by Reinha View Post
One could argue that green/grey/blue skinned races are non-human enough to have another reason for their skin color besides protection from UV radiation. The same way humans become more brown in the sun, fantasy races could become more grey in cold and dry climates, more green in humid and warm climates or more blue from extended nocturnal activity. These changes could surely be accelerated by the means of alchemy and magic.
If there was lore behind it, but as far as I know nothing is specified about skin color change.